Effect of sex and age on outcomes among HIV-2-infected patients starting antiretroviral therapy in West Africa

Abstract

Objectives HIV-2-infected individuals usually initiate antiretroviral therapy (ART) at an advanced age compared with HIV-1 patients, with a potential impact on treatment outcomes. This study aimed to investigate the effect of sex and age on mortality and loss to follow-up (LTFU) among HIV-2-infected individuals initiating ART. Methods Analyses were conducted using the database of the IeDEA–HIV-2 West Africa collaboration. LTFU was considered if the interval between the last visit and the closing date for this analysis was >180 days. Probability of death and LTFU were estimated with Kaplan-Meier methods. A Cox regression model was used to identify factors associated with death and LTFU over the first 24 months on ART. Results A total of 1,825 HIV-2-infected individuals including 60% women were considered for this analysis. The median age, baseline CD4 and follow-up duration were 45 years (IQR[38-52]), 185 cells/mm3 (IQR[95–297]) and 28.8 months (IQR[9.8–58.9]), respectively. Over the first 24 months, the mortality rate was 5.2 per100 pyo (95%CI[4.4-6.1]) and 469 (25.7%) were LTFU. Male sex (HR=1.9; 95%CI[1.4;2.8]), baseline CD4<100 cell/mm3 (HR=4.4 95%CI[1.7;11.1]; ref≥350 cell/mm3), haemoglobin 7.5–10g/dL (HR=2.4 95%CI[1.3;4.4]; ref≥12 g/dL); and body mass index <18 kg/m2 (HR=2.1 95%CI[1.3;3.4]; ref=18-25 kg/m2) were associated with higher mortality over the first 24 months. Similar associations were found for LTFU. Conclusion Mortality and LTFU are high among ART-receiving HIV-2-infected individuals and higher in men than in women. There is a critical need to further determine the causes of poor retention and implement sex specific solutions that improve outcomes in HIV-2 ART programs.

Mortality and survival patterns of people living with HIV-2

“…An analysis was recently conducted among people living with HIV-2 followed-up in the cohort collaboration of the international epidemiologic database to evaluate AIDS in West Africa (IeDEA-WA) (37*). This data set consisted of 5,193 people living with HIV-2 or with both HIV-1 and HIV-2, followed up in seven countries (Benin, Burkina Faso, Cote d’Ivoire, Guinea-Bissau, Mali, Senegal, and Togo).…”

“…Among the 1,825 HIV-2 mono-infected patients who initiated ART between February 1997 and September 2014 and were followed up till December 2014, the median CD4 count at ART initiation was 263/mm 3 ((IQR [159 – 429]). The estimated risks of death after six, 12 and 24 months on ART were 4.1 (CI: 3.2–5.1), 5.5% (CI: 4.4–6.5) and 7.7% (CI; 6.4–8.9), respectively (37*). In addition, patients lost to follow-up were censored after their last contact and the estimated risk of loss to follow-up after six, 12 and 24 months on ART were 10.9% (CI: 9.4–12.3), 16.7% (CI: 14.9–18.4) and 25.7% (CI; 23.7–27.7), respectively (37*).…”

“…Low CD4 cell count and high plasma viral load are also associated with disease progression and mortality among HIV-2 infected patient (13,27,29), and are usually worse in HIV-2 infected men than women, explaining a part of the sex difference observed in mortality (25,30*). Regarding people living with HIV-2 on ART, the IeDEA West Africa collaboration identified male gender (adjusted hazard ratio [aHR]: 1.9; CI: 1.4–2.8; p<0.001), age >=50 years (aHR: 1.44; CI: 0.9–2.1), CD4 count at ART initiation <200 cells/mm3 (aHR: 3.3; CI: 1.3–7.8), body mass index <18 Kg/m 2 (aHR= 2.1; 95%CI [1.2–3.4], p-value =0.005) and haemoglobin rate <10 g/dL (aHR 2.4; 95%CI [1.3–4.4]; p-value =0.005) as factors associated with higher mortality (p=0.001) (37). In the Gambia, Peterson and colleagues identified CD4 cell count <50 per μl (aHR = 2.3; CI: 1.2–4.5] p=0.02), haemoglobin level <8.0g/dl (aHR: 6.2; CI: 2.8–13.8; p<0.001), weight <45kg (aHR: 3.9; CI: 1.8–8.2; p<0.001) and male gender (aHR: 4.9; CI: 2.5–10.8; p<0.001) as factors associated with mortality among people living with HIV-2 and receiving ART (38).…”

In VitroAntiviral Activity of Cabotegravir against HIV-2

“…These distinctions complicate HIV treatment in West Africa and other regions where HIV-1 and HIV-2 cocirculate. Difficulties in differentiating HIV-2 or HIV-1/2 dual infection from HIV-1 infection can lead to the inappropriate use of NNRTI-based regimens in HIV-2infected patients and to premature use of PI-based regimens as first-line ART in patients infected solely with HIV-1 (21)(22)(23). Efforts are needed to simplify ART in areas where HIV-1/HIV-2 discriminatory testing is unreliable and stockouts of HIV-2-active antivirals are commonplace (24).…”

The challenge of discriminating between HIV‐1, HIV‐2 and HIV‐1/2 dual infections

“…Recently, new software for INNO‐LIA interpretation has been introduced providing improved discrimination between HIV types and producing fewer HIV‐positive, untypable results . Another test, the ImmunoComb HIV 1/2 BiSpot (Orgenics, Yavne, Israel), here termed “ImmunoComb”, has also been widely used as a confirmatory test for HIV type discrimination , but during the carrying out of this study the manufacturer ceased production. Although both tests have previously been evaluated with regard to HIV type discriminatory capacity , these evaluations were based on a low number of HIV‐1/2 dually positive patients , outdated software algorithms for INNO‐LIA interpretation , and lack of genomic HIV testing .…”